The Rab Stratosphere 5.5 Sleeping Mat is a warmer option for backpacking in cooler temperatures. From winter yurt trips to summer alpine treks, the Stratosphere combines warm insulation with air-insulated packability to keep you sleeping and hiking comfortably. A 2-way valve eases inflation and deflation, and a water-resistant exterior helps retain the inflated air even when your tent has condensation inside. Rab included a stuff sack that doubles as a pump for breath-free inflation.